answer, depending on other criteria that the author
has. The author can add comments that are not
perceivable in the ICN by using the cmnt attribute.
The qst, ans, hint, and crd attributes refer to the
question itself, the answer, any hints that are to be
displayed in the ICNI, as well as the credits for the
question. For multiple-choice questions, the user can
activate the opt and optValue attributes. To enhance
customisability and learnability during
implementation, the network should initially respond
to the user’s request to create a question node by
producing a perceivable coherent interface window
where only compulsory attributes await input. A
<More Advanced..> button can then give the user
access to the other attributes. Keeping a counter to
determine how often the user interacts with the
<More Advanced..> button, the ASENI can adapt
the perceivable window to make the most frequently
accessed (or all) attributes available on the same
interface window as the compulsory attributes.
Owing to the limited scope of our ASE
prototype, we restricted the available events on the
interface to include discussion-type, exercise-type,
question-type, and link-type events. We briefly
explain how we associated these events with the
topics discussed in the previous phase. When the
author defines (selects) a new topic, one or more
events are either associated with it, or the author is
given the option to select specific events to associate
with the new topic. Whether this association is hard-
coded or created by the author, depends on the type
of topic. For example, the events associated with T
11
through to T
18
are hard coded as a combination of
discussion-type and link-type events since these
topics contain (flat) content that has to be presented
to the user, with little or no interaction expected
from the user. However, for T
9
(‘assignments’), the
author has the option of associating different, or a
combination of event types with each assignment
that is defined. As such, the author might start an
assignment (exercise-type event) by creating a
scenario (discussion-type event), followed by
references (link-type events), before stating the
problem (question-type event). Figure 4 represents a
screenshot from the ASEN prototype showing how
the exercise-type event is depicted.
4.3.2 Auxiliary networks
The structure of an auxiliary network is functionally
integrated with its primary network. Although it is
an autonomous network, it cannot be designed to be
entirely independent of, or in isolation from, its
primary network. We briefly mention three
archetypal nodes for the different auxiliary networks
and mention the related usability aspects. The
troubleshooting event assists one to find the reason
for inexplicable behaviour of the network and also to
find measures to improve it. A help event provides
an explanation of the purpose of another event or
terminology. A tutorial consists of several links
referring mainly to different discussion, simulation
and help events. The auxiliary networks thus add to
the robustness of the ASENI, specifically enhancing
observability and recoverability. Task conformance
is enhanced as help and simulation events can
explain the purpose of the task should the author
misunderstand it. We have not integrated any
auxiliary networks into our prototype at this stage.
4.4 Phase 4: Link plotting
After definition of the network nodes, network
routes are designed and specified in a navigational
table. In a simple situation, the navigational table
can be a simple indexed database. However, in a
fully developed network environment where the
primary networks are augmented with auxiliary
networks, is where a mesh of logical routes possibly
exists. In this case an improved store-and-retrieval
method is required, where entries in the navigational
table are stored in pairs of the format (s,n), where s
refers to the source node's ID and n refers to the next
node's ID. A next-hop routing algorithm uses a one-
step-along-the path approach to identify the next
node en route to the destination. As a first step in
determining a route from source to destination,
possible routes from the source are extracted. If none
of these provide a direct link to the destination,
entries that include the destination address are
extracted next, and their sources are followed
backwards until the shortest route from the source is
determined.
A design challenge is to provide a suitable tool
for route visualisation, route planning and route
creation. This can be achieved by creating an
environment where created nodes are displayed and
the author can visually connect nodes. Observability,
orientation and tracking are greatly enhanced by
making the completed mesh graph perceivable to the
user. However, for large routing tables, the complete
mesh may actually increase complexity of the
interface instead of simplifying it. In such a case,
flexibility parameters such as adaptability and
adaptivity should be given special attention during
the ASENI design, by making provision for the
interface to expose only a route cluster at a time,
instead of the complete mesh.
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